Among patients with HGPS, lonafarnib monotherapy, compared with no treatment, was associated with a lower mortality rate after 2.2 years of follow-up. Study interpretation is limited by its observational design.

Background Hutchinson-Gilford progeria syndrome is an extremely rare, fatal, segmental premature aging syndrome caused by a mutation in LMNA yielding the farnesylated aberrant protein, progerin. Without progerin-specific treatment, death occurs at an average age of 14.6 years from an accelerated atherosclerosis. A previous single-arm clinical trial demonstrated that the protein farnesyltransferase inhibitor, lonafarnib, ameliorates some aspects of cardiovascular and bone disease. This present trial sought to further improve disease by additionally inhibiting progerin prenylation. Methods Thirty-seven participants with HGPS received pravastatin, zoledronic acid and lonafarnib. This combination therapy was evaluated, in addition to descriptive comparisons with the prior lonafarnib monotherapy trial. Results No participants withdrew due to side effects. Primary outcome success was pre-defined by improved per patient rate of weight gain or carotid artery echodensity; 71.0% of participants succeeded (P<0.0001). Key cardiovascular and skeletal secondary variables were pre-defined. Secondary improvements included increased areal (P=0.001) and volumetric (P<0.001–0.006) bone mineral density, and 1.5–1.8-fold radial bone structure increases (P<0.001). Median carotid artery wall echodensity and carotid-femoral pulse wave velocity demonstrated no significant changes. Percentages of participants with carotid (5% to 50%; P=0.001) and femoral (0 to 12%; P=0.13) artery plaques and extraskeletal calcifications (34.4% to 65.6%; P=0.006) increased. Other than increased bone mineral density, no improvement rates exceeded those of the prior lonafarnib monotherapy treatment trial. Conclusions Comparisons with lonafarnib monotherapy treatment reveal additional bone mineral density benefit, but likely no added cardiovascular benefit with addition of pravastatin and zoledronic acid. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00879034 and NCT00916747.